SWAVictor,
Today, I ran across the same problem as described by mritty above.
(OOPs! There is a problem with your form of payment. Please verify your payment information and try again. If you continue to receive this message, you may wish to try an alternate form of payment or you may contact a Southwest Airlines Customer Representative for assistance at 1-800-I-FLY-SWA (1-800-435-9792). (SW900001) )
I am assuming it is still an open trouble ticket?